This article investigates the consequences of the use of genetics in social sciences through one of its main generic instruments, twin studies, a method which consists in quantifying the influence of genetic and environmental factors on a given human behavior by using monozygotic and dizygotic twins. A direct product of geneticists’ strategy of interested generosity analyzed by Aaron Panofsky (2014), the twin studies facilitate interdisciplinary research within social sciences and collaborations between social and natural sciences. Notably, the twin studies appear simultaneously in four different disciplines of the social sciences (criminology, economics, sociology, political science). Beyond the scientific standardization which it entails, the generic instrument of twin studies takes intra-disciplinary local forms. Contrary to geneticists, social scientists tend to use a simplified methodological version of the twin studies model, which is consistent with the concept of « social distance » developed by sociologist of science Harry Collins in his study of the discovery of gravitational waves in physics (2010).